Energy harvesting systems for anticorrosive protection device

In anticorrosive protection of metal underground devices (especially pipelines) are frequently used electric devices such as cathodic protections or electrical drainages. They are often situated in the field, far away from an electric power network. For this reason, their power supply is complicated. Alternative power sources like solar cells, thermoelectric generators, or stray current energy harvesting are sometime used. In case of cathodic protection relatively high power is required - from tens to hundreds of watts, so only a power network or (in some cases) solar cell is applicable. In case of electrical drainage, only power below 1W is required, so powering from alternative power sources may be used. Authors of this paper developed electric regulated drainage with several possibilities of powering, external power source (power network), battery, or energy from current/voltage between railway rails and underground pipeline, where drainage is connected. In this paper an energy harvesting system is described, which acquires energy from current flowing through drainage in forward direction, or from voltage on drainage in a reverse direction. Also laboratory and field testing results are given here. Furthermore, at the beginning of the paper is a basic explanation of electrical drainage principle.